 ### Cylinder

A cylinder is a body of uniform diameter throughout its entire length, whose ends are equal parallel… ### Sphere

A sphere is a solid bounded by a uniformly curved surface, every point of which is equally distant from… ### Conic Sections

Conic sections, cones divided by a plane. ### Accidental Point

"That point in which a right line drawn from the eye parallel to another given right line cuts the picture… ### Metacenter

"The Metacenter is the point of intersection of the vertical line passing through the center of gravity… ### Contours of a cone

The contours of a cone are circles of different sizes, one within another, and the same distance apart,… ### Contours of a half sphere

"The contours of a half sphere are a series of circles, far apart near the center (top) and near together… ### Contours of a concave cone

"The contours of a concave (hollowed out) cone are close together at the center (top), and far apart… ### Cube

A regular solid body, with six equal square sides. ### Prism

A transparent body, with usually three sides and two equal and parallel triangular ends or bases. ### Cylinder

A body of roller-like form, of which the longitudinal section is oblong, and the cross-section is circular. ### Hand and pyramid

A hand holding a square pyramid, suspended by a string. ### Parallelogram

"In the diagram, let AB and AC represent two forces acting upon the point, A. Draw the two dotted lines… ### Symmetry plane

"A crystal has a center of symmetry if an imaginary line is passed from some point on its surface through… ### Symmetry axis

"A crystal has a center of symmetry if an imaginary line is passed from some point on its surface through… ### Symmetry center

"A crystal has a center of symmetry if an imaginary line is passed from some point on its surface through… ### Orthorhombie pyramid

"Crystal faces are described according to their relations to the crystallographic axes. A series of… ### Orthohombie prism

"Crystal faces are described according to their relations to the crystallographic axes. A series of… ### Sulphur crystal

"The forms present upon it are two pyramids of different slope but each intersecting all three of the… ### Crystal of the monoclinic system

"A crystal form does not necessarily make a solid figure. One such an example is this, of the Monoclinic… ### Cube trunctuated by octahedron

"When a corner or an edge of one form is replaced by a face of another form, the first is said to be… ### Octahedron trunctuated by cube

"When a corner or an edge of one form is replaced by a face of another form, the first is said to be… ### Distorted dodecahedron

A distorted dodecahedron ### Twinned cubes

"A penetration twin, since the two individuals interpenetrate each other." — Ford, 1912 ### Twinned octahedron

"A contact twin, since the two individuals lie simply in contact with each other upon a certain plane."… ### Cube and dodecahedron

"A combination of dodecahedron and cube." — Ford, 1912 ### Octahedron and dodecahedron

A combination of octahedron and dodecahedron. ### Dodecahedron and octahedron

A dodecahedron and octahedron ### Cube, octahedron and dodecahedron

A cube, octahedron, and dodecahedron. ### Tetrahexahedron

"The tetrahexahedron is a form composed of twenty-four isoceles triangular faces, each of which intersects… ### Cube and tetrahexahedron

"A cube with its edges beveled by the faces of a tetrahexahedron." — Ford, 1912 ### Trapezohedron

"The trapezohedron is a form composed of twenty-four trapezium-shaped faces, each of which intersects… ### Dodecahedron and trapezohedron

A dodecahedron and trapezohedron. ### Dodecahedron and trapezohedron

A dodecahedron and trapezohedron ### Cube and trapezohedron

"A combination of cube and trapezohedron." — Ford, 1912 ### Trisoctahedron

"The trisoctahedron is a form composed of twenty-four isosceles triangular faces, each of which intersects… ### Octahedron and trisoctahedron

"A combination of a trisoctahedron and an octahedron. It will be noted that the faces of the trisoctahedron… ### Hexoctahedron

"The hexoctahedron is a form composed of forty-eight triangular faces, each of which cuts differently… ### Cube and hexoctahedron

"A combination of cube and hexoctahedron." — Ford, 1912 ### Dodecahedron and hexoctahedron

"A combination of dodecahedron and hexoctahedron." — Ford, 1912 ### Dodecahedron, trapezohedron and hexoctahedron

"A combination of of dodecahedron, trapezohedron, and hexoctahedron." — Ford, 1912 ### Symmetry of pyritohedral class

"The symmetry of the Pyritohedral class is as follows: The three crystal axes of binary symmetry; the… ### Pyritohedron

"This form consists of twelve pentagonal-shaped faces, each of which intersects one crystallographic… ### Diploid

"The diploid is a rare form found only in this class. It is composed of twenty-four faces which correspond… ### Cube and pyritohedron

"A combination of cube and pyritohedron, in which it will be noted that the faces of the pyritohedron… ### Octahedron and pyritohedron

"Combiantion of pyritohedron and octahedron." — Ford, 1912 ### Octahedron and pyritohedron

"A combination of pyritohedron and octahedron." — Ford, 1912 ### Pyritohedron and octahedron

"A combination of pyritohedron and octahedron." — Ford, 1912 ### Pyritohedron, cube, and octahedron

"A cube trunctuated with pyritohedron and octahedron." — Ford, 1912 ### Diploid and cube

"A combination of cube and diploid." — Ford, 1912 ### Symmetry of tetrahedral class

"The symmetry of this class is as follows: The three crystallographic axes are axes of binary symmetry;… ### Positive tetrahedron

"The tetrahedron is a form composed of four equilateral triangular faces, each of which intersects all… ### Negative tetrahedron

"The tetrahedron is a form composed of four equilateral triangular faces, each of which intersects all… ### Positive and negative tetrahedrons

"If a positive and negative tetrahedron occured together with equal development, the resulting crystal…